Originally Posted by RandyCamby
-What happens to the March pump if you shutoff the flow on the output?
Nothing. You're allowed to close a March pump output or throttle it any way you like. They're designed for that.
Should this be done just through an analogue shutoff like on a toilette or is there something relatively easy that can be built into an EletricBrewery-type setup that will also shut-off the pump?
FWIW I don't think you'll see too many people with setups that are programmed to only deliver certain amounts of strike water to the MLT and then shut off automatically.
You need some sort of level switch of some sort or wire and it's going to get in the way and get dirty in the mash making it a pain to clean and possibly not having it work right the next time so you're probably always going to sit there and watch it to make sure it works.
You'd have to move it every time you go to brew which means it needs to be height adjustable. That takes time each brew day to set it right.
What I do is just watch the amount rise in my MLT and then turn off the March pump output valve when I reach that height. It results in (a) less work, (b) less equipment to clean, (c) less chance of things going wrong.
Build what you like of course but I don't see the advantage to something like this myself.